Well-filling means for carburetors



Feb. `25', 1930.

R. F. ENslGN 1,748,332

WELL FILLING MEANS Fon cARBuREToRs Filed Aug. 18, 1926 /f .f 0 o G /5, 1- g] 1]-, f :f 2 fig ,2 f5 2J //7 /5 Mae/afar: ioyf'zzszyfz.

Patented Feb. 25, 1930 PATENT ol-FlcE ROY F. ENSIGN, F LOS ANGELES, CALIFORNIA WELL-FILLING MEANS FOR CARBURETORS Application led August 13, 1926. Serial No. 129,871.

some instances difficulties have beenfencoun-y tered in causing the filling of the well, as such filling has a tendency to rob the fuel nozzle of fuel and thus to cause uneven operation of the carburetor and of the engine to which the carburetor is attached.

It is a general object of this invention to provide an arrangement whereby such an acceleratting well may be filled without robbing the fuel nozzle of fuel necessary for engine operation. How this is done will be best understood from the following detailed dcscription, wherein I explain a simple form of my device, as illustrative ofthe invention7 reference for this purpose being had to the accompanying diagrammatic drawings, in which A:

Fig. 1 is a vertical central section of a carburetor equipped with my device, showing the condition assumed in normal or low speed operation;

Fig. 2 is a similar section showing conditions when the throttlehas been opened for sudden acceleration; and

Fig. 3 is a similar View showing the conditions afterl the throttle has again been closed.,

It will be understood that the drawings not intended to show` many practical details of structure and assembly which enter into such a carburetor and which are well understood in the art.

In the drawings I show at an accelerating well open to atmosphere at its upper end through a port 11 and communicating at lts lower end with a fuel passage 12 that terminates in a fuel nozzle 13 discharging into venturi 14 of the mixture passage M of the carburetor. In the upper piart of the mixture passage M is the usual t ottle T, the upper end of the mixture passage being connectible A to an engine in any known manner.

A well such as here shown will its hit fuel to such a. level as shown at L1 in 1g. 2v

herewith are merely diagrammatic and are' when throttle T is suddenly or widely opened. lThen upon subsequent closure of the throttle to the position shown in Fig. 3, and consequent reduction of the depression at nozzle 13, the well will fill with fuel, but if of a size large enough to function properly onfsome engines it will draw fuel from fuel passage 12 to such an extent as to so completely rob the idling mixture of fuel as to cause stoppage of engine operation. In fact, such a well always has a tendency to draw fuel from the nozzle in filling.

In my invention the accelerating well is not fed with fuel directly from fioat chamber 15, but is fed through fuel port 16 from a fuel 65 passage 17 which also feeds the float chamber through a-restricted port 18. At some convenient point in the structure the fuel passage 17 preferably has an upwardly extending leg 19, one wally of which has an overflow edge 20 70 adjacent the oat chamber, the purposes of which will be described hereinafter.

In the float chamber 15 an suitable float, as the one shown at 21, may e employed to operatethe fuel valve stem 22. This valve -stem seats at 23 on the fuel inlet 24 and controls flow ofl fuel from inlet 24 to fuel passage 17. From passage 17 the flow of fuel to the float chamber is restricted by port 18. Leakage to the fioat chamber around valve stem 22 may be made very small.

When the carburetor is operating at low speed the conditions are substantially as shown in Fig. 1. The fuel level in'float chamber 15, in vertical leg'19 and in accelerating well 10, stands at level L, or substantially so. Fuel is being drawn up through fuel passage 12 and out through nozzle 13 into the mixture passage. If now the throttle is suddenly or widely opened the depression at nozzle 13 is increased, fuel is drawn at a higher rate through that nozzle and therefore fuel is drawn from well' 10, the rate of fuel iow throu h nozzle 13 being temporarily greater than t e rate of iow through restricted fuel port 16. Thus the fuel level in accelerating well 10 may fall to a point shown at L1 in Fig. 2. Level L1 is the limiting low level, as when the fuel reaches that level air will begin to pass from theaccelerating well along with fuel into fuel passage 12 and thus more or less break the suction on the fuel passage. IIoWever in this condition the f'loW of fuel to nozzle 13 is not decreased, owing to the additional effective fuel head on 16 due to the lowering of the fuel level in 10, and owing to the restriction of air flow through 11 and 27. A

During the time of well discharge fuel has been flowing through fuel port 16 into the accelerating well and thus to the fuel passage 12 and nozzle 13, so that during accelerating action the fuel nozzle draws normal or more than normal fuel from port 16 and also draws additional accelerating fuel from the well. Thus, at the same time that fuelA has been drawn from the well, the fuel level in float chamber 15 has necessarily fallen to such a level as indicated at L2 n Fig. 2, as the fuel that has been drawn through port 16`comes from passage 17 which is in communication withfloat chamber 15; and'that fuel can only be replenished by an opening of valve 22 caused by lowering of float 21. The fuel during accelerating action may flow from the float chamber to passage 17 and port 16 either through the restricted .passage 181 or also through the check controlled passage 25. Normally the check valve 26 is closed, butduring any period of sudden increase in fuel requirement this check valve 26 may open as shown in Fig. 2 for flow of fuel from thefloat chamber to the fuel port 16. It may not in all cases be necessary to use the check controlled fuel passage 25; but it is not objectionable in any case as it only allows free flow of fuel from-float chamber 15 to passage 17 and port 16 whenever there is any abnormal demand for fuel.

At the end of any period of abnormal fuel requirement,qas for instance when throttle T is again closed down as shown in Fig. 3, the fuel level in accelerating well 10 will still be low and the fuel level -in float chamber 16 will also still be low, as at L2, and inlet 24 will be open. Check 26 prevents fuel from flowing from passage 17 to float chamber 15.

upon fuel passage 17 and the fuel level in vertical leg 19 immediately rises as is indicated in Fig. 3. The overfiow edge 20 at the upper end of that leg limits the height to which the column of fuel may rise in 19,

limits the pressure which may be brought to desired to use. In cases where that fuel feed pressure is not too great the leg may either be extended high enough that there is no overflow, or the leg might be closed at its top Vor omitted altogether with the same result.

a uniformmaximum. As a result of this excess pressure brought to bear upon port 16 the accelerating well fills quickly and without drawing fuel from fuel passage 12 and nozzle 13. To aid in quick filling of the accelerating A well a fuel passage may be provided also at 27 above the normal fuel level L in the accelerating well. VVhen'ever fuel in 19 stands above passage 27 fuel will flow through that passage-intothe accelerating well and help fill it quickly.

Port 18 is comparatively restricted in size so that, during the operation of filling the accelerating well fuel will not pass freely from passage 17 to float chamber `15. The size of this passageis gauged so that the fuel level in the float chamber will rise to its normal at just about the time the accelerating well is filled to its normal level. And .the relative sizes of well 10 and leg 19 preferably are s0 fixed that the fuel in 19 drops to its normal y level at about the same time that fuel reaches the normal level in 10.

Although the dimensions I will give are to be regarded in no` manner as a restriction upon the invention, I may state certain typical and relative dimensions which will aid in a clear understanding of the operation of the device. Thus, for instance, nozzle 13 may be 1/8 inch in diameter; fuel port 16, le inch in diameter; air bleed 11, le; inch in diameter; fuel passage 27, il?, inch in diameter; fuel port 18, .04.0 inch in diameter and the checked fuel passage 25, g inch in diameter. The air opening at 30 into the upper part of the float chamber may be of any suitable size. The size of the air bleed at 11 together with the size of the air bleed at 27 have a part in controlling the rate at which the accelerating well empties,` as they control the rate at which air enters the upper part of the-accelerating well. i

With any given pressure upon fuel inlet 24, or at any given height of fuel column in vertical leg 19, and with any specific amount of reduction of the pressure on nozzle 13, the

rate at which the accelerating well fills de-l pends primarily upon the relation between the sizes of the ports 16 and 18, and the rela.- tive sizes of these ports is determined in any particular carburetor to cause .the accelerating well to fill in a suitably short time and before or by the time the excess pressure has been taken off passage 17 by the closure of valve 22 consequent upon the raising of the i fuel level in the float chamber to normal.

II claim:

1. In combination with 'a carburetor having a mixture passage, a fuel chamber, a fuel inlet, a fuel inlet valve controlled by the fuel level in the fuel chamber, an accelerating well and a fuel nozzle fed from the accelerating well and discharging into the mixture passage; the combination of means for restrictedly feeding both the accelerating well and the fuel chamber independently of each other from the fuel inlet. l

2. In combination with a carburetor having a mixture passage, a fuel chamber,a fuel inlet, a fuel inlet valve controlled by the fuel level in the fuel chamber, an accelerating well and a fuel nozzle fed from the accelerating well and discharging into the mixture pas# sage; the combination 'of restricted passages leading from the fuel inlet respectively to the accelerating well and the fuel chamber.

3. In combination with a carburetor having a mixture passage, a fuel chamber, a fuel inlet to which fuel may be fed under pressure, an accelerating well and a fuel nozzle fed from the accelerating well and discharging into the mixture passage, fuel being delivered from said chamber to the mixture passage only through the accelerating well; the combination of means controlled by the fuel level in the fuel chamber for applying fuel pressurt from the fuel inlet to the accelerating wel Y 4. In combination with a carburetor having a mixture passage, a fuel chamber, a fuel inlet to which fuel may be fed under pressure, an accelerating Welland a fuel nozzle fed from the accelerating well and discharging into the mixture passage; the combination of means for applying restrictedly A'and independently torthe accelerating well and fuel chamber atleast a partof the fuel pressure at the inlet.

` 5. In combination with a carburetor having a mixturepassage, a fuel chamber, a fuel I inlet, a fuel inlet valve controlled by the fuel tively.

level in the fuel chamber, an accelerating well and a fuelnozzle fed from the accelerating well and discharging into the mixture passage; the combination of a fuel passage communicatingwith the fuel inlet under control of said valve, an upward leg extension of the fuel passage having an overflow to the fuel chamber, and two restricted passages communicating between the fuel passage and the act'zelerating well and fuel chamber, respec- 6. In ing a mixture passage, a fuel chamber, a. fuel inlet, a fuel inlet valve controlled by the fuel level in the fuel chamber, an accelerating well and a fuel nozzle fed from the ,accelerating well and discharging into the mixture passage; the combination of a fuel passage comcombination with a carburetor hav-A inlet, a fuel inlet valvecontrolled by the fuel level in the fuel chamber, an accelerating well and a fuel nozzle fed from the accelerating well and discharging into the mixture passage; the combination of a fuel passage c'olnmunicating with the fuel inlet under control of said valve, an upward leg extension of the fuel passage having an overflow to thefuel chamber, and two restricted passages communicating between the fuel passage and the accelerating well and fuel chamber, respectively, and a fuel opening adapted to pass fuel from the upper part of the leg into the accelerating well. u

8. In combination with a carburetor having a mixture passage, a fuel chamber, a fuel inlet, a fuel inlet valve controlled by the fuel level in the fuel chamber, an accelerating well and a fuel nozzle fed -from the accelerating well and discharging into the mixture passage; the combination of a fuel passage communicating -with the fuel inlet under control of'said valve, an upward leg extension of the fuel passage having an overflow to the fuel chamber, two restricted passages communicating between the fuel passage and the acceleratingl well and fuel chamber, respectively, and a fuel opening adapted to pass fuel from the upper part of the leg into the accelerating well, said opening being abg'e the normal fuel level in the leg and we 9. In combination with a carburetor having a mixture passage, a fuel chamber, a fuel inlet, a fuel in let valve controlled by the fuel level in the fuel chamber, an accelerating well well and discharging into the mixture passage; the combination of means forrestrictedly passing fuel from the fuel inlet to the accelerating Well and means for restrictedly passing fuel from the fuel inlet to the fuel chamber, the relative restrictions of said two means being so proportioned that the well will fill with fuel from said inlet during the time 4the fuel in the fuel chamber is rising to normal level.

10. In combination with a carburetorhaving a mixing passage, azfuel chamber, a fuel nozzle fed from the fuel chamber, and a fuel inlet to which fuel may be fed under pressure the combination of means controlled by the .fuel level in the fuel 4chamber for applying fuel pressure from the fuel inlet to the fuel nozzle independently of the fuel chamber. 11. In combination With a carburetor having a mixing passage, a fuel chamber, a fuel 5l nozzle fed from the fuel chamber, and a fuel inlet to which fuel maybe fed under pressure; the combination of means for restrictedly feeding fuel from the fuel inlet to the uelv nozzle and the fuel chamber independently of each other.

In Witness that I claim the foregoing I have hereunto subscribed my name this 9th day of August, 1926.

' ROY F. ENSIGN. 

